Having finished with BlackHat, I checked out of the Flamingo and moved to DefCon’s new location this year, the Rio. This was an enormous upgrade from the Riviera, the previous location. For one, the conference center is nearly 50% bigger, and it’s beautiful. Traffic flow was greatly improved, despite record attendance (~12,000, from estimates I’ve heard, up 20% from last year.) It was crowded, but it was a manageable crowd, and I managed to get into everything I wanted to, save for a talk in Track 2 (by far the smallest of the 5 presentation rooms.) What’s more, the DefCon Goons improved things as the conference went along (they always do), so Saturday went even better than Friday.

I started the first day with 1o57’s talk on the new DefCon badge. This year’s badges were non-electronic (for the first time in several years) — they were antiqued titanium discs with the Eye of Ra and various codes inscribed in them with a water knife. Apparently making the 10,000 DefCon badges actually used the entire supply of sheet titanium in the United States at the time. Bright side of them being non-electronic: they actually had them before the con started! There has been a history of the badges getting hung up in customs on the way from China, but the non-electronic badges were produced in the USA. 1o57 designed an elaborate puzzle contest around the badges, but I can’t say much about it as I didn’t participate this year. There was, however, a very nice-looking code wheel on the floor of the Rio convention center rotunda that was key to the game and gave the room a nice DefCon look, so it was appreciated even by non-participants.

I spent the next couple of hours exploring the non-talk aspects of DefCon (none of the sessions in those slots were particularly interesting to me) and bought up some DefCon shirts and a couple of 2600 Hacker Calendars. I also donated $170 to the Electronic Frontier Foundation in my name and my wife’s, though I didn’t actually end up going to the party to which that entitled me admission (the donation and not the party was the primary purpose anyway.)

I dropped into Mark Weber Tobias’s physical security talk, called Insecurity: An Analysis Of Current Commercial And Government Security Lock Designs, which involved some hilarious attacks on “high-security” physical locks. You know those locks with 5 vertically-arranged pushbuttons you see in every airport or government building? They pop right open if you stick a neodymium-iron-boron magnet on the side. A keycard/keypad electronic lock with a USB port on the bottom for reprogramming is impervious to electronic attacks… but opens if you shove a paperclip to the back of the USB port. This sort of attack was ubiquitous — simple modifications that made sophisticated electronic locks open in purely mechanical ways. The overall point is that to get through a door, you do not have to open the lock — you have to actuate the mechanism that the lock actuates. Sometimes this is really easy.

The next talk was entitled Why Airport Security Can’t Be Done FAST, about the TSA’s Future Attribute Screening Technology. This project intends to detect malicious intent, based on biometrics and facial cues, kind of like an electronic Cal Lightman. The problem, in short, is the standard Bayesian statistical issues that always come up when trying to detect something vanishingly rare like terrorism. The top 10 airlines in the world carry a billion passengers per year — the top 5 US carriers alone carry 500 million per year. How many of these are terrorists who actually intend to blow up a plane that flight? Let’s be very conservative and pretend 100 people try to board an American plane with the intent to blow it up every year (probably an enormous overestimate.) Now let’s imagine my FAST system is 99.9% accurate at detecting terrorists — sounds great, doesn’t it? Let’s get that into our airports immediately! But wait… 99.9% accurate means it will probably catch all 100 terrorists. It’ll also catch 500,000 innocent people — 0.1% of the 500 million passengers. So if FAST points you out as a terrorist, there’s a 0.0002% chance it’s right! Due to the base rate fallacy, a 99.9% accurate terrorist detector’s alarms are false positives 99.9998% of the time. Oops.

What do you bet the real FAST isn’t 99.9% accurate, either?

I next attended the EFF Year in Civil Liberties panel for a summary of legal issues in information security, privacy, and free speech. This was followed by the Hackerspace Panel, about hackerspaces and DefCon groups around the country and what they do to encourage innovation and bring hackers, makers, and other interested people together. Both panels went very well, especially given that the Q&A nature of panels often makes them hit-or-miss.

Friday night at DefCon is surprisingly free of events — about all that’s going on is the Black Ball and the DefCon Pool Party. I met up with the DC206 group again, had some dinner, and mostly hung out at the pool party for the evening and discussed the day’s events and other topics in hackerdom. Frankly, talking about interesting topics (in a hot tub outside with DJs spinning techno in the background, no less) beats most parties anyway.